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AVR430 

 

 

8124C-AVR-10/08 

4 Detailed description 

4.1 Power 

The  MC300  has  two  power  circuits.  Vin  for  powering  driver  ICs  and  voltage 
regulators, and Vmotor (Vm) for powering the output stage (MOSFETs). The separate 
power supply for the motor, Vm, allows the use of motor voltages outside the voltage 
range of the driver ICs. This also isolates noise generated by the output stage/motor. 

There is a separate ground plane for each power circuit, GND for Vin and GNDmotor 
(GNDm) for Vm. This is done to separate the high currents to the motor from the rest. 
The  ground  planes  are  connected  together  at  one  single  point,  under  the  J3 
connector (shown in Figure 4-1). 

A  regulated  power  supply  for  Vcc  is  included  on  the  board.  The  voltage  for  Vcc  is 
selectable by J2, if open Vcc = 5V and if set Vcc = 3.3V.  

4.1.1 Input 

The MC300 can be powered in two ways. With J3, a four pin 3,81mm pitch connector, 
separate  power  supplies  can be  connected to  Vin and Vm.  But it  is  also  possible  to 
power  the  MC300  from  a  single  DC-Jack  connector,  J5.  J5  is  connected  to  Vin  and 
Vm via diodes as shown in Figure  4-1. When  J5  is used  as power input, the  supply 
voltage must not exceed 20V and maximum current is 5A. 

Figure 4-1. 

MC300 Power input.

 

 

4.1.2 Fuses 

Vin is protected by a resettable 0,75A polyfuse (F1). If the current through it exceeds 
0,75A, the fuse will heat up and go into a high resistance mode for as long as the load 
is retained, and will reset when allowed to cool down. 

A  socket  mounted  6,3A  5x20  mm  fuse  protects  Vm  (F2).  Using  a  socket  mounted 
fuse allows the user to replace and  change  it easily.  When developing  software it is 
also practical to not power the output stages until correct operation of the software is 
ensured, and this can be done by simply removing the fuse. 

4.1.3 LEDs 

Vcc, Vin and Vm each have their own green LED to indicate if voltage is present. The 
Vcc LED (D3) is connected to Vcc by a resistor and hence it will emit less light when 
Vcc is 3,3V. Vin and Vm LEDs (D1 and D2) have a constant current sources, so they 
have a constant intensity even if Vin or Vm changes. 

Содержание 8-bit AVR Microcontrollers AVR430: MC300

Страница 1: ...d Electric specifications Driver circuit Vin 10 20V Motor Vm 0 40V Immax 6A Dimension 100x100mm 1 Introduction The MC300 is a general purpose power stage board able to drive brushless DC brushed DC and stepper motors The board is designed to be a flexible platform for developing motor control applications Power and all signals needed for a controller AVR CPU are available on the left side of the b...

Страница 2: ... the Hall sensors Vm Vin and Vcc each have their own LED to indicate power 2 1 Specifications MC300 maximum ratings with components as delivered Input Vin 10 20VDC Vm 0 40VDC Immax 6A Output ratings Vcc 3 3 5V Imax 0 5A Vha 5V Imax 0 1A The driver stage consists of four half bridges capable of 40V 30A Warning Other components such as shunt resistors limit the maximum current to 6A 2 1 1 Necessary ...

Страница 3: ... Table 2 2 The connectors are mounted on the same 0 1 grid The grid is positioned so the connectors will fit an angled pin header on a prototype Vero board shown in Figure 2 1 2 2 2 Power and motor connectors The board has two power connectors located on the top one 4 pin 3 81mm connector J3 and one DC jack J5 with 2 0mm center tap J3 allows for separate power inputs to Vin and Vm while J5 powers ...

Страница 4: ... for location of jumpers Table 2 1 Jumpers and their functions Designator Use and settings J1 VHa Selects voltage source to Hall sensors VHa J1 open VHa not connected J1 pin 2 3 connected VHa Vcc J1 pin 1 2 connected VHa 5V from separate regulator J2 VCC Selects voltage from onboard regulated supply Vcc J2 connected Vcc 3 3V J2 open Vcc 5V ...

Страница 5: ...hase X Highside control input 16 J11p8 XL Input Phase X Lowside control input 17 J13p1 GNDm Motor ground Vmotor 18 J13p2 Vmotor Output Vmotor filtered divided 19 J13p3 ShCom Output Voltage over ShCom filtered divided 20 J13p4 ShU Output Voltage over ShU filtered divided 21 J13p5 U Output BackEMF phase U filtered divided 22 J13p6 ShV Output Voltage over ShV filtered divided 23 J13p7 V Output BackEM...

Страница 6: ...tant components and jumper information are written on the silk screen For individual component placement refer to the component floorplan Figure 3 1 MC300 PCB layout In Figure 3 1 the following areas are marked 1 Device board connector 2 Power connectors 3 Motor connector 4 Phase area 5 Indicator LEDs for power ...

Страница 7: ...d and above shunt resistor 4 Bootstrap voltage testpoint denoted Vboot 5 MOS Gate voltage testpoints denoted VGl low side and VGh high side 3 1 2 Common shunt and filters dividers The common shunt R62 with testpoints is found above phase U and denoted ShCom Filters dividers for Vm ShCom and Vn are found on the left of the phase areas 3 2 Schematics component floorplan and bill of materials The sch...

Страница 8: ... Vm But it is also possible to power the MC300 from a single DC Jack connector J5 J5 is connected to Vin and Vm via diodes as shown in Figure 4 1 When J5 is used as power input the supply voltage must not exceed 20V and maximum current is 5A Figure 4 1 MC300 Power input 4 1 2 Fuses Vin is protected by a resettable 0 75A polyfuse F1 If the current through it exceeds 0 75A the fuse will heat up and ...

Страница 9: ...bridge for phase U is shown in Figure 4 2 Figure 4 2 Phase U half bridge 4 2 1 High side driving considerations The high side of the half bridge uses a bootstrap circuit This means the duty cycle and the on time are limited by the requirement to refresh the charge in the bootstrap capacitor If the driving logic fails to do this the gate voltage to the high side MOS will decrease and the RDS will i...

Страница 10: ... to a zero ohm resistor and the zero ohm resistors on each phase ShU R27 ShV R38 ShW R49 and ShX R64 should be replaced with appropriate shunt resistors 4 3 1 Shunt feedback filters The voltages over the shunt resistors ShCom ShU V W X are fed to a filter damping block ShU as shown in Figure 4 4 The board is shipped with a filter that consists of a 10k ohm resistor in series with a 10nF capacitor ...

Страница 11: ...neutral provides feedback to device board 4 4 1 Back EMF feedback filters Each phase U V W X and the center tap Vn are fed via a filter damping block to the device board interface The block for phase U is shown in Figure 4 5 The board is shipped with a zero ohm resistor so it has no damping filter function The signals are named U V W X and Vn after going through the filter blocks Vmotor Vm is also...

Страница 12: ...dge drivers IR2101S can handle up to 600V but the layout of the PCB spacing between tracks should be considered before operation at high voltages If filters dividers for Vm U V W or X have been mounted verify that they can handle Vm 4 5 2 Current limitations For an Im 5A use power connector J3 and not DC Jack J5 If an Immax larger than 6A is required components listed in Table 4 2 are affected Tab...

Страница 13: ...TUTORY WARRANTY RELATING TO ITS PRODUCTS INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTY OF MERCHANTABILITY FITNESS FOR A PARTICULAR PURPOSE OR NON INFRINGEMENT IN NO EVENT SHALL ATMEL BE LIABLE FOR ANY DIRECT INDIRECT CONSEQUENTIAL PUNITIVE SPECIAL OR INCIDENTAL DAMAGES INCLUDING WITHOUT LIMITATION DAMAGES FOR LOSS OF PROFITS BUSINESS INTERRUPTION OR LOSS OF INFORMATION ARISING OUT OF THE USE O...

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